Guest and host represent the two sides of the reciprocal duty of hospitality. Hospitality to the stranger was an important part of many of the cultures that descended from the Proto-Indo-European-speaking people. You can see it in stories from Greek mythology, from the Bible, from Germanic folklore… In Proto-Indo-European (as with Latin hospes) the same word was used for both roles in the relationship, but English is never content with one word when two will do. Guest came to us by way of our ancient native Germanic branch, while host arrived in the thirteenth century from Latin through French.
The bulk of our French-derived words arrived in English, as you may recall, along with the swords of a very large number of strangers — a host, in fact, of rather hostile strangers. It isn’t really so surprising that English should have acquired words from that stranger root with a more bellicose connotation.
Still, the Old French derivations from that same PIE root also gave us the names of a variety of different places where strangers can go for care: hospital (13th century meaning “inn”, and “a place for the sick” not until the 16th century), hotel (first “public official residence” in the 17th century and “inn” in the 18th), and hostel and hostelry (13th century “inn.” These words had become obsolete by the 17th century but were revived by Sir Walter Scott in the 19th, and the “youth hostel” meaning is from the 20th century.)
Finally, the host in a church communion service comes from Latin hostia, “sacrifice,” but is probably ultimately related to the root “stranger” in its more inimical connotation. Another unwilling guest, a hostage, is less clear. Linguists are undecided on whether it’s derived from the same root or another. And then there’s the possibility of a visitation from another plane, from a ghost, which looks and sounds like it ought to derive from that Proto-Indo-European root ghos-ti-, but is in fact completely unrelated.
Ghosts aside, we’re still left with the fact that almost any situation your Thanksgiving celebration presented probably included at least one word from that same ancient root.
[Picture: Family Dinner, woodcut by Max-Karl Winkler, from a Cookie Recipe book, 1977 (Image from DCimPRINT).]